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pentazoid
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Homework Statement
Look up the enthalpy of formation of atomic hydrogen in the back of the book. This is the enthalpy change when a mole of atomic hydrogen is formed by dissociating 1/2 mole of molecular hydrogen (the more stable state of the element). From this number, determinethe energy needed to dissociate a single H2 molecule , in electron-volts.
Homework Equations
PV=3100 J
delta(H)=delta(U)+P*delta(V)
H=U+PV
The Attempt at a Solution
find delta(U)
delta(U)=delta(H)-P*delta(V)
found delta(H) to be delta(H)=-217.97 kJ
According to the standard table T=298 K and P=1 bar=1atm?
R=8.31 J/K
PV=RT=(8.31 J/K)(298 K)=2.5 kJ
H-PV=(-217.97 kJ)-(2.5 kJ)=-220.5 kJ
Did I find delta(U) correctly?